Abstract
Abstract: :
Purpose: A high correlation exists between the lipophilicity of a molecule and its corneal penetration rate. The purpose of this study was to identify which molecular properties are responsible for the superior bioavailability of moxifloxacin. Secondly, a mathematical model was developed to predict corneal permeability based upon in vitro data and physiochemical properties of these antibiotics. Methods: Permeabilities of moxifloxacin, ciprofloxacin, norfloxacin, ofloxacin, levofloxacin, lomefloxacin, and gatifloxacin were measured in MDCK (Madin–Darby canine kidney) cells. In vitro corneal penetration rates (cm/s) for five of the fluoroquinolones were reported previously. (Fukada M. and Sasaki, K. In vitro topically applied fluoroquinolone penetration into the anterior chamber. Nippon Ganka Gakkai Sasshi 99:532, 1995). Aqueous solubility, distribution coefficient and pKa were determined experimentally. Results: Moxifloxacin, showed higher lipophilicity, aqueous solubility and MDCK cell permeability than the other fluoroquinolones tested. MDCK cell permeability was highly correlated with both lipophilicity (R2 = 0.92) and corneal permeability (R2 = 0.93). Conclusions: MDCK cell permeability can serve as a predictive model for corneal penetration for fluoroquinolone antibiotics. As a consequence of its higher lipophilicity and greater aqueous solubility, moxifloxacin achieves greater penetration through the cornea and other ocular tissues than any of the other fluoroquinolones tested.
Keywords: antibiotics/antifungals/antiparasitics • anterior segment • computational modeling